HKS AT Fluid Cooler Universal | (1602-SA001)HKS AT Fluid Cooler Universal Application for Automatic Transmissions Part #: 1602 SA001 Overview The HKS AT Fluid Cooler is designed to help maintain optimal transmission fluid temperatures in automatic vehicles, especially those subjected to spirited driving, tuning, or heavy duty use. Excessive heat in automatic transmission fluid can lead to decreased viscosity, which may cause increased wear on internal components such as disks and brakes,